Vehicle seat assembly with air bag seam rupturing force concentrator

ABSTRACT

A vehicle seat assembly  10  with a frame  26 , a seat pad, and an air bag assembly housing, an inflator, and a folded air bag that is inflated to unfold and project outwardly from the seat through an air bag release seam  28  when the seam is ruptured. The vehicle seat assembly has a spinnaker-shaped reinforcement panel  56  with a leading nose  49  secured to the release seam  28  and an anchored end edge  52  that is secured to the frame  26  or to a trim cover  18 . The spinnaker-shaped reinforcement panel  56  is movable in response to inflation of the air bag with sufficient force to puncture the release seam  28 , thereby allowing the tear seam  28  to open and allowing the air bag to pass therethrough.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Application No. 10 2007 011823.8, filed on Mar. 12, 2007, the disclosure of which is herebyincorporated in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a vehicle seat assembly, and in particular, aseat assembly including an air bag. The seat assembly includes a tearseam which upon being ruptured by a force concentrator facilitatesegress of the air bag during deployment.

2. Background Art

Vehicles and associated seating systems are designed to protect anoccupant from injury after the vehicle sustains a hit havinglongitudinal and lateral force components. The side air bags offerprotection from the adverse consequences of a blow having primarily alateral component. Such devices may be in the form of a side air curtaindisposed in a headliner of the vehicle, or an air bag disposed within avehicle seat assembly. One limitation of air bags that are locatedwithin a seat assembly is that the air bag needs to break through theseating material before it can fully deploy to protect a vehicleoccupant. During deployment, such an air bag may encounter foam, orother seat pad materials. It must then break through a seat trim coverin order to escape from the seat assembly.

Such encounters may impede or prohibit full, speedy deployment. Anotherlimitation is that the air bag should break through the cover materialat a predetermined location to optimize its effectiveness.

Prior vehicle seat assemblies equipped with side air bags andmanufacturing methods are disclosed in U.S. Pat. Nos. 5,816,610;5,860,673; 5,938,232; 5,967,603; 6,003,938; 6,045,151; 6,237,934;6,299,197 and 6,588,838, for example.

SUMMARY OF THE INVENTION

The invention broadly includes a vehicle seat assembly that in at leastone embodiment, has a frame, a seat pad, and a trim cover extending atleast partially over the seat pad. The trim cover includes a first(e.g., front) and a second (e.g., side) portion that together form atear or release seam. In one embodiment, a brace (such as stitching)extends between the first and second portions of the trim cover at thetear seam to releasably secure the portions of the seam.

An air bag assembly is preferably mounted on or associated with theframe at least partially within the trim cover in a spaced relationshipfrom the air bag release seam. In accordance with one embodiment, theair bag assembly has a (rigid or soft) container and a lid that house aninflator and a folded air bag. In some cases, the container mayeffectively resemble a sack or a bag. Upon inflation, the bag unfoldsand ultimately projects outwardly from the seat through the air bagrelease seam when the seam is in a second, opened position.

Preferably, a spinnaker-shaped or onion-skin shaped reinforcement panelis provided that has a anchored, stationary edge portion that is securedalong at least some of its length to the frame by a mounting means, suchas one or more mounting studs, (e.g., nuts and bolts) or to a rear trimpanel. At the other end of the spinnaker-shaped reinforcement panel isan a leading nose portion that is secured to one or both portions of therelease seam of the trim cover. In some embodiments, thespinnaker-shaped reinforcement panel passes around one side of the airbag assembly.

In operation, the leading nose portion of the spinnaker-shapedreinforcement panel exerts a concentrated, directed force upon therelease seam in response to inflation of the air bag. When the forceexerted is sufficient, the leading nose portion of the panel rupturesthe release seam. In this way, the seam opens and progressively unravelsor the stitching breaks, thereby allowing the air bag to pass through.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view of a portion of a seat assembly inaccordance with the present invention;

FIG. 2 is a fragmentary sectional view of the seat assembly shown inFIG. 1, taken through line 2-2;

FIG. 3 is an alternate embodiment of the assembly depicted in FIG. 2;and

FIGS. 4-7 are fragmentary sectional views of alternative ways to affix aleading nose portion of a spinnaker-shaped reinforcement panel to arelease seam.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

FIG. 1 illustrates one embodiment of a seat assembly 10 that isconstructed in accordance with the present invention. The seat assembly10 includes a seat back 12 and seat pad 16 at least partially covered bya trim cover 18. As is well known, the seat assembly 10 includes a seatcushion or seat bottom (not shown). The trim cover 18 may be made of anysuitable material such as cloth, vinyl or leather, etc. In at least someembodiments (e.g. one of which is depicted in FIG. 3), a relativelyrigid plastic molding 14 can be provided in the rear area of the seatassembly 10 to provide support and/or for aesthetics.

In at least one embodiment, the seat pad 16 is made from a moldedpolymeric material, such as a polyurethane foam. The use of a polymericfoam material to construct the seat pad 16 can be cost effective and canprovide the flexibility needed to easily change the shape of the seatpad for different types of seat assemblies. Of course, other types ofpolymeric materials may be molded to form the seat pad 16.

Disposed within the seat back 12 is an air bag assembly, such as a sideair bag assembly 20 (FIGS. 2-3). While the side air bag assembly 20 isshown on the seat back 12, which is a usage for which it has particularutility, it is also possible for the side air bag assembly to beutilized with a seat cushion or bottom, even though the seat back usageis specifically disclosed. Also, as illustrated, the air bag assembly 20is located at an outboard lateral side or extremity of the seat toprovide protection against adjacent vehicle structure. But it is alsopossible to have the side air bag assembly located at the inboardlateral side to provide protection against an adjacent vehicle occupantand to also have side air bag assemblies at both outboard and inboardlocations for protection in both lateral directions.

Referring now to FIGS. 2-3, the air bag assembly 20 includes an air bagand an inflator (not shown). The assembly 20 is configured to supply aninflation fluid such as gas to the air bag, thereby facilitating itsdeployment. In at least one embodiment, the air bag assembly 20 alsoincludes a housing 40 which at least partially surrounds the air bag andthe inflator. In most embodiments, the housing 40 includes a container46 secured to the seat frame 26 and a lid 48 that may open like a clamshell away from the container 46. It should be appreciated that neitherthe container 46 nor the lid 48 of the housing 40 need be formed from arigid material. In some applications, in alternate embodiments, thecontainer 46 and/or the lid 48 may be formed from a relatively softmaterial such as a woven or non-woven textile or a plastic sheet. Insuch cases, when the air bag is inflated, the forces of deployment willbe exerted upon the spinnaker-shaped reinforcement panel 56. Oneconsequence is that as the air bag travels outwardly beneath the trimcover 18, a sharp inwardly directed pull will be exerted upon and willlacerate the release seam 28.

Also shown in FIG. 2 is a portion of the seat frame 26 which can be usedfor mounting the seat assembly 10 to a vehicle. The seat pad 16 isdisposed proximate the frame 26 and the air bag assembly 20 and may bedirectly attached to the frame 26 at various points. An edge of the trimcover 18 forms part of an air bag release seam 28 (FIGS. 2-7) which inat least one embodiment is proximate to a side 33 of the seat pad 16.

In the embodiments shown in FIGS. 2-3, the trim cover 18 includes endportions 31, 33 that cooperate to form seam 28. Preferably, the endportions 31, 33 have one or more suitable connections or braces, shownschematically as stitching with ends 56 and 58, that cooperate to securefolded trim cover edges (shaped in some embodiments as knuckles) thatcomprise the seam 28. As also shown in the embodiment illustrated inFIG. 3, the ends 31 and 33 of cover 18 are connected to each other atseam 28 via any suitable connection member, such as stitching or threador frangible staples or braces 60 that are shown schematically to helpmaintain seam 28 in a closed position before air bag deployment. Whilestitching 60 is shown schematically in FIGS. 2-7, it should beunderstood that other connection members or materials such as abreakable plastic, nylon, or fabric stitch or thread could be used.

The air bag assembly 20 is preferably located within the trim cover 18and may be conventionally mounted, such as on the frame 26 in a spacedrelationship from the release seam 28. The folded air bag, upondeployment, is inflated by inflation fluid from the inflator to unfoldand project outwardly from the seat 10, ultimately through the air bagrelease seam 28 of the trim cover 18.

With continuing reference to FIGS. 1-3, a spinnaker-shaped reinforcementpanel 56 is made of any suitable relatively inelastic material. Thespinnaker-shaped reinforcement panel 56 has an anchored edge portion 52that in some embodiments (FIG. 2) is secured to a seam 49 at the side orrear of the seat. Alternatively (FIG. 3), the anchored edge portion 52is secured to the frame 26 by a suitable means, such as one or moreJ-clips 47. Extending from the anchored edge 52, in one embodiment, thereinforcement panel passes along the outboard side of the housing 40. Alayer of foam in some embodiments may lie between the panel 56 and thecontainer 40.

As the air bag deploys, the lid 48 of the housing 40 opens and movesoutwardly to the left, with reference to the cross-sectional viewsdepicted in FIGS. 2-3. A tensile force is then exerted upon thespinnaker-shaped reinforcement panel 56. Its longer, anchored edge 52 isfirmly attached, as discussed above. Since the panel 56 is relativelyinelastic, the forces of airbag deployment and opening of theclamshell-shaped housing 48 are communicated to the leading or pointedend 49 of the panel. That end is subjected to a sharp, inwardly directedtugging force. Since pressure equals force divided by area and thedenominator at the leading nose 49 is relatively small, the pressureexerted upon the seam 28 that is secured to the panel is concentratedand augmented. Localized rupturing then occurs in the release seam 28.That localized rupture is propagated along the seam away from the smallarea at which the nose 49 of the panel 56 is attached.

As noted above, when the air bag 22 deploys, the lid 48 moves outwardly,like a clam shell. The container 46 part of the housing 40 isimmobilized by its attachment via a bolt or fastener (not shown) to theseat frame 26. Outward movement of the clam shell lid 48 urges the panel(in relation to the frame of reference of FIGS. 2-3) to the left, oroutwardly in relation to the center of the seat assembly. This actioncauses tension in the spinnaker-shaped reinforcement panel 56. Since theanchored edge 52 of the spinnaker-shaped reinforcement panel 56 isimmobilized, the tension induced in the spinnaker-shaped reinforcementpanel 56 produces a sharp, localized, inwardly directed pull at the tearseam 28. Upon deployment of the air bag, the spinnaker-shapedreinforcement panel 56 will lacerate the release seam 28, therebyfacilitating the bag's egress. Thus, the air bag can extend through therelease seam 28 and outside the seat assembly 10 into an occupantprotection position.

Optionally, the reinforcement panel 56 may comprise woven or non-wovencloth material, which may include natural or synthetic materials such asnylon. One material that is found to be effective is a polyestermaterial, of the type from which the air bag may be manufactured.Regardless of the type of material used, the panel 56 can be helpful inreducing friction on the air bag as it deploys. Although a polymer suchas nylon may be particularly beneficial, even a fleece material willhelp reduce the friction on the air bag. This is because the panel 56inhibits contact between the deploying air bag 22 and the trim cover 18.

This, in turn can also help to reduce the deployment time for the airbag and/or the amount of inflation fluid required to deploy the air bag.

The spinnaker-shaped reinforcement panel 56 can be made by any suitableprocess and of any suitable material such as nylon, PP, and PE. In atleast one embodiment, it is made of a somewhat bendable material such asa wire or band. In alternative embodiments, a portion of thespinnaker-shaped reinforcement panel 56 may comprise a string, band,wire, textile, mesh, tab, or a strap.

If the seam 28 is formed from continuous stitching that extends alongits length, the nose 49 of the spinnaker-shaped reinforcement panel 56may only be connected to one or more threads of the stitching, sincebreaking one thread in a continuous stitching will allow the stitchingto unravel, thereby allowing seam 28 to open.

In at least one embodiment, the spinnaker-shaped reinforcement panel 56has a length of 30 to 100 cm (centimeters), in other embodiments of 60to 100 cm, and in yet other embodiments of 60 to 90 cm. In someembodiments, the spinnaker-shaped reinforcement panel 56 has an averagethickness of 0.01 to 5 mm (millimeters), in other embodiments of 0.05 to4 mm, and in yet other embodiments of 0.2 to 2.0 mm.

Turning now to FIGS. 4-7, it will be appreciated that FIG. 4 depicts anembodiment wherein the release seam 28 includes a brace 60 thatreleasably attaches respective facing knuckle portions of folded overends of a side and a front trim cover. In FIG. 5, the nose portion 49 issecured on an inside of the knuckle portion of the side trim cover 18. Alabel member 62 is also secured between the knuckle portion of the frontand side trim covers. In that embodiment, the label member 62 protrudesoutside the trim covers and release seam 28. Optionally (FIG. 7), theleading nose portion 49 of the reinforcement panel 56 itself serves as alabel member 62.

An alternative embodiment is shown in FIG. 6. In that figure, the noseportion 49 is secured between the knuckle portions of the side and fronttrim cover so that it is invisible when viewed from the outside of theside and front trim covers.

It will be appreciated that in other embodiments, the seat assembly mayinclude multiple spinnaker-shaped reinforcement panels, such as thepanel 56. In such embodiments, the leading nose portion 49 will besecured at various locations along the release seam 28.

As required, detailed embodiments of the present invention are disclosedherein. However, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousalternative forms. The figures are not necessarily to scale. Somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore the specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for the claims and/or a representative basis forteaching one skilled in the art how to variously employ the presentinvention.

Moreover, except where otherwise expressly indicated, all numericalquantities in this description and in the claims indicating amounts ofmaterials or conditions of reactions and/or use are to be understood asmodified by the word “about” in describing the broader scope of thisinvention. Practice within the numerical limits stated is generallypreferred. Also, unless expressly stated to the contrary, thedescription of a group or class of materials as suitable or preferredfor a given purpose in connection with the invention implies thatmixtures of any two or more members of the group or class may be equallysuitable or preferred.

While embodiments of the invention have been illustrated and described,it is not intended that these embodiments illustrate and describe allpossible forms of the invention. Rather, the words used in thespecification are words of description rather than limitation, and it isunderstood that various changes may be made without departing from thespirit and scope of the invention.

1. A vehicle seat assembly with a frame, a trim cover extending at leastpartially over a seat pad and including a first and a second end portionto form a release seam, a brace extending between the first and secondend portions of the trim cover at the release seam to maintain therelease seam in a closed position before air bag deployment, an air bagassembly at least partially within the trim cover, the air bag assemblybeing in a spaced relationship from the air bag release seam, the airbag assembly housing an inflator and an air bag that is inflated by theinflator to unfold and project outwardly from the seat through the airbag release seam when the air bag seam is at least partially ruptured,the vehicle seat assembly comprising: a spinnaker-shaped reinforcementpanel with an anchored edge portion secured to the frame and a leadingnose portion attached to the release seam, the spinnaker-shapedreinforcement panel passing at least partially around a side of the airbag assembly, and around a padded region positioned adjacent to a sideof the air bag assembly, the leading nose portion of thespinnaker-shaped reinforcement panel being movable in response toinflation of the air bag with sufficient force to rupture the releaseseam, thereby opening the release seam and allowing the air bag to passtherethrough.
 2. The vehicle seat assembly of claim 1, wherein thespinnaker-shaped reinforcement panel passes between the air bag assemblyand the trim cover.
 3. The vehicle seat assembly of claim 1, wherein thebrace releasably attaches respective facing knuckle portions of foldedover ends of a side and a front trim cover.
 4. The vehicle seat assemblyof claim 3, wherein the leading nose portion is secured on an inside ofthe knuckle portion of the side trim cover.
 5. The vehicle seat assemblyof claim 3, wherein the nose portion is secured between the knuckleportions of the side and front trim cover.
 6. The vehicle seat assemblyof claim 3, wherein the nose portion is secured between the knuckleportions of the side and front trim cover so that the panel is invisiblefrom outside the trim covers.
 7. The vehicle seat assembly of claim 3,further including a label member, wherein the nose portion and the labelmember are secured between the knuckle portions of the side and fronttrim cover.
 8. The vehicle seat assembly of claim 3, further including alabel member, wherein the label member extends from the nose portion andthe nose portion and the label member are secured between the knuckleportions of the side and front trim cover.
 9. The vehicle seat assemblyof claim 1, wherein the brace is selected from the group consisting ofcontinuous stitching, intermittent stitching, a plastic staple,ultrasonic welding and a glue.
 10. The vehicle seat assembly of claim 1,wherein the spinnaker-shaped reinforcement panel comprises a memberselected from the group consisting of a strap, a plastic, an array ofwires, an assembly of chords, a textile and combinations thereof. 11.The vehicle seat assembly of claim 1 in which there are multiplespinnaker-shaped reinforcement panels.
 12. The vehicle seat assembly ofclaim 1, wherein the spinnaker-shaped reinforcement panel has ananchored edge that is secured to the frame.
 13. The vehicle seatassembly of claim 1, wherein the spinnaker-shaped reinforcement panelhas an anchored edge that is secured to a trim cover.
 14. In a vehicleseat assembly having a seat pad associated with a frame, a trim coverextending over the seat pad and including a release seam, an air bagassembly at least partially within the trim cover, the air bag assemblybeing provided with a container and a lid, the container being securedto the frame so that the air bag assembly lies in a spaced relationshipfrom the release seam, the air bag assembly housing an inflator and afolded air bag that is inflated to unfold and project outwardly from theseat through the air bag release seam when the air bag seam is in anopened position, a spinnaker-shaped reinforcement panel extendingbetween the frame and the release seam, the spinnaker-shapedreinforcement panel passing around a side of the air bag assembly, thespinnaker-shaped reinforcement panel having a leading nose detachablyattached to the release seam and an anchored edge secured to the frame,the leading nose being movable in response to inflation of the air bagwith sufficient force to lacerate the release seam, thereby allowing therelease seam to open and allow the air bag to pass therethrough, amethod for deploying the air bag, comprising the steps of: inflating theair bag; tensioning the spinnaker-shaped reinforcement panel byoutwardly directed forces of air bag deployment acting upon the panel;and lacerating the release seam by a sharp, inwardly directed tugexerted upon the release seam by tensioning forces applied to thespinnaker-shaped reinforcement panel.
 15. A vehicle seat assembly with aframe, a trim cover extending at least partially over a seat pad andincluding a first and a second end portion to form a release seam, abrace extending between the first and second end portions of the trimcover at the release seam to maintain the release seam in a closedposition before air bag deployment, an air bag assembly at leastpartially within the trim cover, the air bag assembly being in a spacedrelationship from the air bag release seam, the air bag assembly housingan inflator and an air bag that is inflated by the inflator to unfoldand project outwardly from the seat through the air bag release seamwhen the air bag seam is at least partially ruptured, the vehicle seatassembly comprising: a spinnaker-shaped reinforcement panel with ananchored edge portion secured to the frame and a leading nose portionattached to the release seam, the spinnaker-shaped reinforcement panelpassing at least partially around a side of the air bag assembly, andaround a padded region positioned adjacent to a side of the air bagassembly, the leading nose portion of the spinnaker-shaped reinforcementpanel being movable in response to inflation of the air bag withsufficient force to rupture the release seam, thereby opening therelease seam and allowing the air bag to pass therethrough, wherein thebrace releasably attaches respective facing knuckle portions of foldedover ends of a side and a front trim cover; and a label member, the noseportion and the label member being secured to the release seam.
 16. Thevehicle seat assembly of claim 15, wherein the nose portion and thelabel member are secured between the knuckle portions of the side andfront trim cover.
 17. The vehicle seat assembly of claim 15, wherein thelabel member extends from the nose portion and the nose portion and thelabel member are secured between the knuckle portions of the side andfront trim cover.